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DON LEMON, CNN ANCHOR: An unforgettable voice.

Silenced after a troubled life.

One year after her tragic death, a look at Whitney Houston; her life, her music.

It's been one year since Whitney Houston's life ended tragically here in the Beverly Hills hotel. A megastar's life cut short in the same dramatic fashion in which she lived. Now we take a look back at her life, her final days and her death.

That legendary ballot, that blinding beauty, that breathtaking voice.

Whitney Houston, the shy jersey girl who belted her way to superstardom. Six Grammys, and a record seven consecutive number one singles. For a time, she was pop's greatest love of all.

KELLY PRICE, SINGER: To hear her voice was a miracle because for anybody to be able to do with a voice what she did with hers speaks to a divine order.

ALEXIS CHIU, EXECUTIVE EDITOR, IN-TOUCH WEEKLY: There were many sides to Whitney. There was a performer, the consummate professional. There was the addict and you never knew which way you were going to get.

LEMON: If Houston was blessed by the heavens, she was most certainly cursed with her own demons. A contradiction right up to her final days.

PRICE: This was not a woman who was depressed, upset, high, drunk.

GERRICK KENNEDY, REPORTER, LOS ANGELES TIMES: It was immediate. You could smell the stench of cigarettes and of liquor, and I am like, oh, my God, she is a mess right now.

LEMON: Whitney Houston died here at the Beverly Hilton on February 11th, the voice of a generation silenced forever. A tragic ending to a life filled with promise that was almost preordained. With the gospel legend for a mother, and a cousin named Dionne Warwick, Houston was born to sing. CLARENCE WALDRON, CONTRIBUTING EDITOR, JET MAGAZINE: When we first saw Whitney, when you first heard Whitney, you knew there was something special happening here.

LEMON: Legendary music producer Clive Davis certainly knew. He discovered Houston and changed her life forever. He packaged and polished the 19-year-old sensation into a pure pop princess, at least on the surface.

Alexis Chiu, now executive editor in "In-Touch Weekly" reported on Whitney's death for "People" magazine.

CHIU: One source who worked with Whitney told us that she definitely was not a goody two-shoes in any sense of the word.

LEMON: Houston's bad girl side may have ultimately drawn her to R&B bad boy Bobby Brown.

CHIU: She was a girl from the streets of Newark and she fell in love with a bad boy with a good voice. So, you know, her fan, yes, very shocked. Those who knew her best really weren't surprised.

LEMON: Houston and Brown traded rings in 1992, a personal high matched only by a professional one that very same year. "The bodyguard" grossed more than $400 million and launched the top selling soundtrack of all time.

But even as the crossover superstar commanded millions for movies like "the preacher's wife," she increasingly struggled with her fame.

Did she ever talk to you about the stress of fame?

GARY CATONA, WHITNEY HOUSTON'S VOCAL COACH: She said to me, you don't know what it is like being me. I am stressed out all the time.

LEMON: That stress was only compounded by Houston's rocky marriage.

CHIU: They were very happy at first but pretty soon the relationship turned pretty volatile, and when she was under pressure, she tended to turn to drugs and alcohol.

LEMON: When Houston began a string of missed appearances and cancelations, many pointed their finger at Bobby Brown for his wife's mounting troubles with drugs.

JENNIFER HOLIDAY, SINGER: I hate to say that she had started before she had met Bobby Brown.

LEMON: Houston's increasingly erratic behavior even played out before the cameras in the short-lived reality show "being BOBBY Brown." But when Brown spoke to CNN in 2005, he insisted he and his famous wife were finally sober.

BOBBY BROWN, SINGER: I am working on a year and a half of sobriety. And my wife, she is working on her year, so we're really doing good, and I am proud of her. LEMON: Yet her attempts at recovery only ended in relapse for Houston and the years of drug abuse had taken their toll.

CATONA: I was shocked at her condition. Her vocal condition.

LEMON: What happened to Whitney Houston's voice?

CATONA: I think that the psychological impact of being who she was drove her into lifestyle habits that ultimately were destructive.

LEMON: By May 2011 Whitney Houston was divorced. Her attempt at a comeback a year earlier was in shambles. With all of these crushing personal setbacks, she entered into a voluntary outpatient program for drug and alcohol treatment. Friends say she just needed a break.

KIM BURRELL, WHITNEY HOUSTON'S FRIEND: I know that she was pacing herself because she was preparing for the movie. I don't know exactly what she went through to do that.

LEMON: That movie was "Sparkle," and by the time Whitney Houston began doing press for the film, she did seem like a different woman. "Access Hollywood's" Shaun Robinson did the last one on one interview with her.

SHAUN ROBINSON, ANCHOR, ACCESS HOLLYWOOD: When I looked Whitney Houston in her eyes, I thought that this woman is coming back.

LEMON: But looks can be deceiving, especially when you are talking about Whitney Houston.

Her final days when we return.

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LEMON: With a new movie and a new sparkle of her home, a seemingly healthy Whitney Houston started the new year poised to perhaps make that long awaited comeback. But behind the scenes some now all too familiar and alarming behavior.

Alexis Chiu, now with "In Touch Weekly" reported on Whitney's death for People Magazine.

CHIU: Her friends told us that even though she had successfully gone to rehab and had this great experience filming "Sparkle," there are always temptations and you know, unfortunately, she started partying again and spending time with perhaps the wrong people and just fell right back into that sad spiral.

LEMON: Three days before the annual Grammy awards show, Whitney Houston was staying here at the Beverly Hilton. It is here where over several days sources say the pop superstar was seen consuming considerable amounts of alcohol and acting erratically.

Gerrick Kennedy of "the L.A. Times" was covering a pre-Grammy press event at the Beverly Hilton when the singer raised eyebrows at the hotel pool. KENNEDY: One of the conversations I had with a Grammy staffer was that security were getting calls from guests that she was doing handstands by the pool. It was like, oh, that's pretty bizarre.

LEMON: And then there was this. Kennedy says Houston smelled of cigarettes and alcohol when she burst in on her mentor Clive Davis.

WHITNEY HOUSTON, SINGER: Come say hi to your godfather.

UNIDENTIFIED FEMALE: OK.

HOUSTON: Come say hi to your God-dad.

So, I am just like, oh, my god, you are a mess right now and you are embarrassing yourself. I am embarrassed for you.

LEMON: But the pop star appeared anything but disheveled or disoriented later that night.

Whitney Houston attended a pre-Grammy party at this Hollywood night club. And as she walked the red carpet, witnesses say she had it together and was on her best behavior.

Adam Ambrose is a publicist for "True Hollywood."

ADAM AMBROISE, PUBLICIST, TRUE HOLLYWOOD: She walked along here with -- holding hands, in fact, with Bobbi Kristina and they both looked radiant when they arrived. They were, you know, looking fantastic.

LEMON: Houston was even up for a little impromptu entertaining. She surprised everyone when she joined her friend, R&B Grammy nominee Kelly Price on stage.

AMBROISE: The place erupted. I mean, it was very sweet. It was actually really touching when she went up.

LEMON: Fun times, but too much of a good time? Not so says Kelly Price. While she says that Houston had champagne at the party, she denies reports that things got out of hand with her friend.

PRICE: This was not a woman who was depressed, upset, high, drunk. She was clearly in her right mind. She was not acting erratic.

LEMON: But "Access Hollywood's" Shaun Robinson says the pictures taken that Thursday night tell a whole different story.

ROBINSON: I said who is that? What the hell happened? What happened in three months that took her from this person who seemed to really have it all together to this person who looked very disheveled and just kind of not there?